Mining Engineering
GATE MN year:2018 PYQs
Build your understanding with focused practice from past exam papers.
Questions 41–50 of 65. Imported answers require independent review unless marked reviewed.
Question 31
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A right conical iron ore stack on level ground of height 10 m has 60% Fe. The height of the conical stack is extended up to 20 m using iron ore of 50% Fe. The angle of repose of iron ore is 38°. The mean grade of the final stack in % Fe is ____________________.
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The feasible region of a linear programming problem is shown in the figure. The maximum value of the objective function
is ____________________.
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Cash flow of a project of duration 4 years is shown. The uniform income ‘R’, in Rs. crores, at the end of 2nd, 3rd and 4th year for an internal rate of return of 10% is ______________.
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The grade values of alumina at three sample locations (A, B and C) in a bauxite deposit are as shown. Using the ‘inverse distance’ method, the computed grade in % alumina at location ‘Z’ is ____________________.
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Economic feasibility of two methods is examined for meeting a targeted mine production. On a yearly basis, the following cost parameters (Rs in crores) are applicable for these methods.
| Method 1 | Method 2 |
|---|---|---|
Fixed cost | 20 | 5 |
Variable cost | 2X | |
The annual rate of production, ‘X’ in million tonnes for which both the methods will yield the same operating cost is ____________________.
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A person standing 50 m away from an HEM experiences 90 dB sound pressure level. If the person moves to a new location that is 70 m away from the HEM, the sound pressure level experienced by the person, in dB, becomes ____________________.
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A portion of a ventilation system has two splits as shown. Split ‘A’ has a resistance of
and a regulator of size 2.0
. The resistance of split ‘B’ in
is _________.
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Air enters a bord and pillar panel at 10 ppm CO and 20.78% O
. The air at the panel return has 80 ppm CO and 20.52% O
. The ‘Graham’s ratio’ for the status of fire in the panel in % is ____________________.Log in to check the answer
You can attempt this question now. Sign in to view the answer key, explanations and discussion.Log in to check answerQuestion 39
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In a sublevel stope, 20 m high excavation is made with ring drilling in a 6 m wide orebody. In an effective shift time of 6 hrs, three rings are blasted resulting in 9 m extraction length. LHDs of 5.0
bucket capacity and cycle time of 5 minutes are used for ore transportation. The number of LHDs required for this operation is _________________.Log in to check the answer
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A coal seam lying at a depth of 200 m is developed by bord and pillar method. Pillars are 30 m centre to centre with a gallery width of 4 m. Unit weight of the overlying strata is 28
. If the pillar strength is 9.32 MPa, the factor of safety of pillar is ___________.Log in to check the answer
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